The Middle Earth: Shadow of Mordor Iron of Death will give you One Bronze Trophy or 10 GamerScore points. You need to issue a Death Threat, and then successfully kill the target.
To get the Middle Earth: Shadow of Mordor Iron of Death Trophy/Achievement you should be able to unlock or buy the Tier 4 Ability “Death Threat.” Go to the northwest side of the map and get hold of an enemy.
You need to dominate him by pressing Square (PlayStation) / X (Xbox) to issue a death threat. Then select “Death Threat” Option from in game options. Choose an Uruk to issue a Death Threat and make a Death Threat towards him, try to choose an easy enemy.
Now all you need to do is reach the location of the Uruk to whom you have just issued the Death Threat and complete the Death Threat by killing him. Use weaknesses for an easy kill.
For those who are still unsure on how to get Middle Earth: Shadow of Mordor Iron of Death Trophy/Achievement, watch the video given below: